摘要
采用熔融的共晶锡铅钎料熔滴与Au/N i/Cu焊盘瞬时接触液固反应形成钎料凸点,随后进行再流焊及老化。对这一过程中的钎料/焊盘界面金属间化合物组织的演化,尤其是Au-Sn化合物的形成及分布进行了研究。结果表明,钎料熔滴与焊盘液固反应形成了Au-Sn界面化合物,铜层未完全反应。在随后的再流焊过程中,界面处的铜层完全消耗掉,镍层与钎料反应形成N i3Sn4界面组织;针状的AuSn4化合物分布于钎料基体中。老化条件下分布于钎料基体中的AuSn4重新在界面沉积,在N i3Sn4层上形成(AuxN i1-x)Sn4层。(AuxN i1-x)Sn4在界面的沉积遵循分解扩散机制,并促进富铅相的形成。钎料与焊盘反应过程中Au-Sn化合物的演化及分布直接影响钎料与焊盘的连接强度。
Solder bump was fabricated with Sn-Pb eutectic solderdroplet on Au/Ni/Cu pad.The solder/pad was then subject to reflowsoldering and aging at125℃.The IMC evolution at solder/pad interfaceduring this process,especially the formation and distribution of Au-Sncompound were investigated.The results showed that Au-Sn compoundforms at solder/pad interface during contact reaction,and Au does not re-act fully with solder droplet.During the subsequent reflow soldering,allAu layer at interface is consumed,Ni layer reacts with solder,whichleads to the formation of Ni3Sn4compound at the interface.AcicularAuSn4can be found in the solder bulk.AuSn4particles redesposites atthe interface as a continuously(AuxNi1-x) Sn4layer during aging at125℃.The redesposited(AuxNi1-x)Sn4at solder/pad interface followsdecomposition-diffusion mechanism.At the same time,a lead-rich phaseemerges with AuSn4redeposition at the interface.The shear strength ofsoldered joint is mainly determined by this evolution and distribution ofAu-Sn compound.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2006年第1期53-56,共4页
Transactions of The China Welding Institution
基金
总装备部预研究项目(51418070105HT0143)
